Fiberglass epoxy question RV-9A slider

[ron sterba]

I am in the process of building up my a lip over the top of my windshield and down the sides with the 1 1/2" fiberglass cloth. I have installed my first layer last night. For each additional layer do I have to let dry AND SAND each layer before I add the next layer? Or can I just keep adding layers?

Thanks Ron in Oregon

[pilot2512]

I am not up to that part yet, but you should be doing all the layers at once. If you let it cure then you have to scruff it up for the next layer to adhere. I'm sure someone more knowledgeable will chime in.

Jay

[rightrudder]

You can do it either way. I opted to apply the fiberglass over three sessions, with some sanding in between. I preferred this route because I didn't feel rushed and I could think about it a little between sessions.

[bret]

I did all mine in one session also with two layers of CF in the mix around upper windshield, all on packing tape, next day popped it off and then sanded for a month on the bench, then Sika onto the plane.

[Mike S]

If you do it layer by layer, you can use peel ply to give a usable surface to the hardened layer.

http://www.clcboats.com/shoptips/epo...se-fabric.html

[airguy]

Each time you put a new layer onto a CURED layer, you'll want to sand it down first - but you can lay up 3 or 4 layers at once, sure.

Make sure you mix a colorant into the epoxy if you don't want it clear, I made mine black.

[ron sterba]

Thanks,guys,I have peel ply. So sanding is still in my future,darn. OK I like the sikaflex idea since I used it on both windshield and canopy. Just knew ,just darn knew it that I should have posted earlier. That's what I get for my midnight lay up! Great ideas guys thanks. Got some carbon fiber so I'll use some of that too.

Always appreciative!

Ron in Oregon.

[lr172]

If the resin is still "green," you can put on another layer with no prep. If it is fully cured, it must be fully sanded for mechanical adhesion. Whether or not it is still "green" is variable based mostly upon which activator and the ambient temp while curing. a conservative rule is, If it is soft enough to dig a fingernail in, it is still green.

Generally, if you want to layer on previous hard layers, put the second layer on as soon as the first gets firm. I prefer wet layers. Sanding is a pain and chemical bonding is preferred over mechanical adhesion. multiple cured layers promotes excess resin. Wet layers are easier to keep tight.

the epoxy to plexi bond is quite poor. For my targa stripe, I layed up over packing tape and removed after curing. I then sanded and bonded it to the plexi with Urethane adhesive made for plexi bonding.

Larry

[airguy]

And let your edge run long (aft on the aircraft) so you can cut the ragged edge to a clean finish and sand it down smooth.

[ron sterba]

Thanks Larry, thanks,my thoughts were running a little amuck about green. How many layers shouldI install? I bought rolls of 1", 1 1/2" & 2" of fiberglass with a hem sewn in on both edges. With one layer down and sanded ( need new thumb and forefinger). My next layer I wanted carbon fiber. Are there any special cutting procedures on this material. Mines in a roll one foot wide by 5 foot long and the strands are 3/32" wide and all going in same direction and a simple thread going 90 degrees across.( up & under & over ) it does not look like the weave of fiberglass cloth mating. Did I buy the wrong carbon fiber material? I am assuming the carbon fiber strands should run length wish across the windshield edge,yes/ no?

I at a rest stop on the interstate so I haven't been able to check the links the guys have sent in their threads. Maybe these questions might be in them,so forgive me for not checking them. Been a crazy busy day here in Oregon with the humidity getting up near 30% today.

Ron in Oregon RV9A